1. Technical Field
The present invention relates to a light source device which emits a laser beam, and a projector including the device
2. Related Art
To date, a laser diode has been known which loads a prescribed amount of energy on a laser medium, reflects laser beams emerging from the laser medium with mirrors provided at both ends of the laser medium, and amplifies an output of the laser beams at the laser medium. (For example, refer to JP-A-6-132595 (refer to Pages 2 to 3 and FIGS. 1 and 2)).
A laser diode disclosed in JP-A-6-132595 is a second harmonic light generator with a mirror structure formed at one end of a light source, a non-reflecting structure formed at the other end, and a nonlinear optical unit provided facing the non-reflecting structure in the second harmonic light generator, a laser beam emitted from the non-reflecting structure by the nonlinear optical unit is wavelength converted, and a second harmonic light is generated. Also, a mirror structure being formed at each end of the nonlinear optical unit, a mirror structure, from among the mirror structures, on a side not facing a light source has a high reflectance with respect to a basic wavelength, and a low reflectance with respect to the wavelength converted second harmonic light, while a mirror structure on a side facing the light source is a non-reflecting structure. Then, while a laser beam emitted from the light source is reflected by the mirror structure on an end surface of the nonlinear optical unit on the side not facing the light source, and the mirror structure formed at one end surface of the light source, and energy of the laser beam amplified, the laser beam wavelength converted by the nonlinear optical unit emerges from the mirror structure of the nonlinear optical unit on the end surface on the side not facing the light source.
However, in a case of a heretofore known second harmonic light generator such as that disclosed in JP-A-6-132595, as a laser beam is not band narrowed, a problem has been raised as an example in that an emission wavelength of a laser diode fluctuates depending on temperature, an emission wavelength interval of a laser beam emitted from a light source is wider than an allowable interval of a converted wavelength of a nonlinear optical unit, light of a wavelength band not wavelength converted increases, and a conversion efficiency deteriorates.